Vulnerability Note VU#304725

Original Release Date: 2018-07-23 | Last Revised: 2018-08-17

Overview

Bluetooth firmware or operating system software drivers may not sufficiently validate elliptic curve parameters used to generate public keys during a Diffie-Hellman key exchange, which may allow a remote attacker to obtain the encryption key used by the device.

Description

Bluetooth utilizes a device pairing mechanism based on elliptic-curve Diffie-Hellman (ECDH) key exchange to allow encrypted communication between devices. The ECDH key pair consists of a private and a public key, and the public keys are exchanged to produce a shared pairing key. The devices must also agree on the elliptic curve parameters being used. Previous work on the "Invalid Curve Attack" showed that the ECDH parameters are not always validated before being used in computing the resulted shared key, which reduces attacker effort to obtain the private key of the device under attack if the implementation does not validate all of the parameters before computing the shared key.

In some implementations, the elliptic curve parameters are not all validated by the cryptographic algorithm implementation, which may allow a remote attacker within wireless range to inject an invalid public key to determine the session key with high probability. Such an attacker can then passively intercept and decrypt all device messages, and/or forge and inject malicious messages.

Both Bluetooth low energy (LE) implementations of Secure Connections Pairing in operating system software and BR/EDR implementations of Secure Simple Pairing in device firmware may be affected. Bluetooth device users are encouraged to consult with their device vendor for further information.

Since the vulnerability was identified, the Bluetooth SIG has updated the Bluetooth specifications to require validation of any public key received as part of public key-based security procedures, thereby providing a remedy to the vulnerability from a specification perspective. In addition, the Bluetooth SIG has added testing for this vulnerability within its Bluetooth Qualification Program. The Bluetooth SIG has also released a public statement regarding the vulnerability.

Impact

An unauthenticated, remote attacker within range may be able to utilize a man-in-the-middle network position to determine the cryptographic keys used by the device. The attacker can then intercept and decrypt and/or forge and inject device messages.

Solution

Apply an update

Both software and firmware updates are expected over the coming weeks. Affected users should check with their device vendor for availability of updates. Further information for vendors is provided in the Vendor Status section below.

Vendor References

Addendum

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QUALCOMM Incorporated

Notified: January 18, 2018 Updated: July 25, 2018

Statement Date: July 24, 2018

Status

Affected

Vendor Statement

Qualcomm is aware of the recently published security research on Bluetooth pairing protocols, and we are actively deploying mitigations to our customers. Providing technologies that support robust security and privacy is a priority for Qualcomm, and we encourage end users to update their devices when patches become available.

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

Addendum

There are no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Dell EMC

Updated: July 30, 2018

Statement Date: July 25, 2018

Status

Not Affected

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

Addendum

There are no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Microsoft

Notified: February 06, 2018 Updated: July 20, 2018

Statement Date: July 20, 2018

Status

Not Affected

Vendor Statement

The vulnerability does not affect Microsoft Windows.

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

Addendum

There are no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

RSA Security LLC

Updated: July 25, 2018

Statement Date: July 25, 2018

Status

Not Affected

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

RSA BSAFE® Crypto-C ME and Crypto-J are NOT affected.

Addendum

There are no additional comments at this time.

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Bluetooth SIG

Notified: February 06, 2018 Updated: February 06, 2018

Status

Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Addendum

There are no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Linux Kernel

Notified: March 05, 2018 Updated: March 05, 2018

Status

Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Addendum

There are no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.